Field
Advancements in multi-radio mesh networks are needed to provide improvements in performance, efficiency, and utility of use.
Related Art
All references cited herein (if any), including patents, patent applications, and publications, are hereby incorporated by reference in their entireties, whether specifically incorporated or not, for all purposes.
Multi-radio mesh networks are becoming increasingly more popular in commercial deployments since they have a higher potential traffic carrying capacity than single radio networks. Each wireless interface (or radio) of a mesh node can be tuned to a different channel and can be used in parallel with the other wireless interfaces of the node. In an ideal scenario, a node with N wireless interfaces would have N times the capacity of a node with a single wireless interface. When a network of nodes with a single radio is compared to the same network of nodes with N radios, the capacity of the second network may increase by more than N over that of the first network due to channel assignments that reduce interference among nearby links and multi-hop degradation.
Mesh networks tend to have a dense topology, which is intended to increase their redundancy. This enables fast recovery when a node fails, through the use of backup forwarding paths. The density of the topology however, increases the interference in the network, and makes an optimal channel assignment difficult, especially when a small number of radios and channels are available.
To perform channel assignment in a mesh network, we could simply select N channels and assign each to the N radios of each node. However, such a channel assignment makes no attempt to reduce wireless interference in the network or improve performance even further, which is possible due to the presence of multi-radio nodes. Interference in the wireless environment spans a greater distance than the transmission range of a wireless device (typically interference range is assumed to be twice the nominal transmission range) and as a result, to achieve maximum throughput on a link, all nodes that are within the interference range of that link (typically assumed to be those that are 2 wireless hops away) should be configured to channels different from the ones on the link.